1 files changed, 33 insertions, 8 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 34a8952de8dd..dcf2448c16f1 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1302,20 +1302,45 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
         ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
         if (ret < 0)
                 return ret;
-        ret = btrfs_previous_item(fs_info->extent_root, path,
-                                        0, BTRFS_EXTENT_ITEM_KEY);
-        if (ret < 0)
-                return ret;
 
-        btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
+        while (1) {
+                u32 nritems;
+                if (path->slots[0] == 0) {
+                        btrfs_set_path_blocking(path);
+                        ret = btrfs_prev_leaf(fs_info->extent_root, path);
+                        if (ret != 0) {
+                                if (ret > 0) {
+                                        pr_debug("logical %llu is not within "
+                                                 "any extent\n", logical);
+                                        ret = -ENOENT;
+                                }
+                                return ret;
+                        }
+                } else {
+                        path->slots[0]--;
+                }
+                nritems = btrfs_header_nritems(path->nodes[0]);
+                if (nritems == 0) {
+                        pr_debug("logical %llu is not within any extent\n",
+                                 logical);
+                        return -ENOENT;
+                }
+                if (path->slots[0] == nritems)
+                        path->slots[0]--;
+
+                btrfs_item_key_to_cpu(path->nodes[0], found_key,
+                                      path->slots[0]);
+                if (found_key->type == BTRFS_EXTENT_ITEM_KEY ||
+                    found_key->type == BTRFS_METADATA_ITEM_KEY)
+                        break;
+        }
+
         if (found_key->type == BTRFS_METADATA_ITEM_KEY)
                 size = fs_info->extent_root->leafsize;
         else if (found_key->type == BTRFS_EXTENT_ITEM_KEY)
                 size = found_key->offset;
 
-        if ((found_key->type != BTRFS_EXTENT_ITEM_KEY &&
-             found_key->type != BTRFS_METADATA_ITEM_KEY) ||
-            found_key->objectid > logical ||
+        if (found_key->objectid > logical ||
             found_key->objectid + size <= logical) {
                 pr_debug("logical %llu is not within any extent\n", logical);
                 return -ENOENT;